Sample Autonomic Nervous System Pathways

Shown here are examples of visceral or autonomic pathways that allow the CNS to regulate blood pressure (BP) and heart rate (HR).

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When blood pressure (BP) declines, pressure receptors (baroreceptors) in the wall of the aortic artery detect the change and a corrective, involuntary reflex begins.

Action potentials (electro-chemical impulses) are generated in autonomic sensory (afferent) neurons and conducted to the cardiac regulatory center in the brainstem.

From the brainstem, response impulses are conducted down the spinal cord by CNS neurons.

These impulses are then transmitted to sympathetic motor neurons (efferent neurons) that originate in the spinal cord. The motor neurons conduct the impulses out of the spinal cord sympathetic ganglion located next to the vertebral column. Here, synapses occur and a second set of neurons carry the impulses on to the heart.

On their arrival, the impulses stimulate the hear to beat faster and more forcefully.